• Journal of the Korean Ceramic Society
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• v.36 no.2
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• pp.145-150
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• 1999

Gd1-xSrxMnO3(0$\leq$X$\leq$0.6) as the cathode for solid oxide fuel cell was synthesized by citrate process and studied for its crystal structure, electrical conductivity, thermal expansion coefficient (TEC), and investigated reactivity with 8 mol% yttria stabilized zirconia(8YSZ) or Ce0.8Gd0.2O1.9 (CGO). The crystal structure of Gd1-xSrxMnO3 changed from orthorhombic (0$\leq$X$\leq$0.3) through cubic (0.4$\leq$X$\leq$0.5) to tetragonal structure (X=0.6). When Sr contents was increased, the electrical conductivity of Gd1-xSrxMnO3 was inthose of La1-xSrxMnO3, 8YSZ and CGO if Sr content was above 30mol%. TEC of Gd1-xSrxMnO3 was increased with Sr content. After heat treatment at 1300$^{\circ}C$ for 48 hours, reaction product of Gd1-xSrxMnO3 and 8YSZ was SrZrO3. However CGO had no reaction product with Gd1-xSrxMnO3.

• Journal of the Korean Ceramic Society
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• v.38 no.1
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• pp.45-51
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• 2001

고체산화물 연료전지의 삼상 계면의 길이를 증가시키기 위해 Glycine-Nitrate Process(GNP)를 이용하여 환원극 재료인 L $a_{0.5}$S $r_{0.5}$Mn $O_3$(LSM)과 전해질 재료인 C $e_{0.8}$G $d_{0.2}$ $O_{1.9}$(CGO)를 합성하였다. 적당한 합성조건을 찾기 위하여 글리신의 양을 달리하여 분말을 합성한 결과 LSM의 경우 글리신이 양이온 몰수의 2배일 때 perovskite상이 얻어졌으며 비표면적은 34$m^2$/g 이었다. 합성된 LSM과 CGO 분말을 50:50 wt%로 혼합하여 제작된 환원극을 screen-printing법으로 코팅한 후 각각 1200, 1300, 1350 및 140$0^{\circ}C$에서 4시간 동안 소결한 후 80$0^{\circ}C$에서 power density와 양극과전압 등을 측정한 결과 130$0^{\circ}C$에서 소결한 단위전지에서 최대 309 mW/$ extrm{cm}^2$의 power density를 얻을 수 있었다.다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.1
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• pp.18-25
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• 1998

G $d_{0.2}$C $e_{0.8}$ $O_{1.9}$(CGO) for electrolyte and L $a_{0.5}$S $r_{0.5}$Mn $O_3$(LSM50) for cathode in Solid Oxide Fuel Cells(SOFC) were synthesized by citrate process. Specimens were prepared with sintering temperatures at 110$0^{\circ}C$, 120$0^{\circ}C$ and 130$0^{\circ}C$, which were fabricated by slurry coating with citric acid contents. Interfacial resistance was measured between cathode and electrolyte using AC-impedance analyzer. With various citric acid content, the degree of agglomeration for the initial particles changed. Also sintering temperature changed the particle size and the degree of densification of cathode. Factors affecting the interfacial resistance were adherent degree of the electrolyte and cathode, distribution of TPB(three phase boundaries, TPB i.e., electrolyte/electrode/gas phase area) and porosity of cathode. By increasing the sintering temperature, particle size and densification of the cathode were increased. And then, TPB area which occurs catalytic reaction was reduced and so interfacial resistance was increased.sed.sed.d.